1. Field of the Invention
The present invention generally relates to a wheel, and more particularly to a reinforced vehicle wheel capable of sustaining heavy loads and having a long service life, without being unduly heavy. The reinforced wheel of the present invention is particularly well-suited for use with a four-wheel-drive vehicle but may be used wherever a wheel having especially high strength is required.
2. Description of Related Art
Vehicle wheels generally are subjected to heavy loads. In particular, wheels on four-wheel-drive vehicles must be capable of withstanding especially high stresses since such vehicles commonly are driven over rough terrain. A four-wheel-drive vehicle wheel must have high loadability (i.e., be capable of sustaining heavy loads) and high fatigue strength, yet maintain a reasonable weight.
A wheel commonly is formed from multiple pieces (i.e., a multi-piece wheel). For example, one type of two-piece wheel has two wheel sections each having a center portion and a rim portion which are aligned and joined to form a wheel hub and wheel rims, respectively. Another type of two-piece wheel is formed of a unitary rim section which is secured to a separate hub section by way of rivets or other fasteners. One type of three-piece wheel has inner and outer rim portions which are joined to a hub. In contrast, a one-piece wheel is made from a single piece by e.g., casting or forging and rolling. Regardless of whether a wheel is multi-piece or one-piece, the wheel is highly susceptible to failure in the region where the hub transitions into the rim (the "transition region"). The transition region has a relatively sharp bend where the periphery of the substantially vertical hub contacts the substantially horizontal rim and hence is particularly prone to failure. Wheel failures commonly include tangential cracks or catastrophic failure along the circumferential edge of the transition region. In the case of multi-piece wheels, the wheel pieces typically are joined together by fasteners in the outer region of the hub adjacent the transition region. It is not unusual for such a multi-piece wheel to sustain cracks at the assembly holes through which the fasteners are inserted. Exotic materials and complicated wheel designs may be used to minimize the possibility of wheel failure. However, these approaches are relatively costly. A wheel having high loadability, long service life, relatively light weight, and simple construction at relatively low cost is highly desirable.